Framed panels made of shattering materials tend to shatter when subjected to shock and the shattered fragments of the panels may be propelled at high speeds into the room in which the framed panel is located, causing injury to personnel and/or damage to the room.
Non-shattering panels, such as panels made of laminated glass, polycarbonates or glass coated in protective film, are frequently used to prevent such injury to personnel and damage to property, and are generally effective for this purpose. However, it is not uncommon, eg during an external explosion, for the entire panel, whether made of shattering or non-shattering material, to be forced out of the frame and to travel at high speed into the room in which it is located. This is particularly problematic when the panel is held in a relatively weak frame, such as a timber frame. Such panels can travel at up to 10 m/s (approximately 30 feet per second) and can cause serious injury to personnel, as well as significant damage to property.
Attempts have been made to arrest the movement of such a panel from the surrounding frame by reinforcing the frame with steel bars. However, it has been found that such steel bars can also be forced away from the frame and driven into the room at high speed, potentially causing serious injury to personnel and damage to property.